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Technology · head to head

Envoy vs GNAT Pro

Envoy logo

Envoy

Technology

A high-performance L7 proxy written in C++ that is configured by an API rather than a config file, and is usually deployed under a control plane.

From
Free
Free plan
Yes
Full reviewWebsite
GNAT Pro logo

GNAT Pro

Developer Tools

Software development environments and toolchains for Ada, C/C++ and Rust

From
On request
Free plan
No
Full reviewWebsite

The short version

  • Only Envoy has a free tier, so it costs nothing to try first.
  • Each has a real cost: Envoy the configuration surface is very large and hand-written bootstrap YAML runs to hundreds of lines for routing that Nginx expresses in twenty, which is why nearly every production deployment sits under a control plane and inherits that control plane's constraints as well.; GNAT Pro no pricing published on website; requires contacting AdaCore directly for quotes
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Envoy and GNAT Pro actually diverge.

Attributes where Envoy and GNAT Pro differ
AttributeEnvoyGNAT Pro
Starting priceFreeOn request
Pricing modelopen-sourcequote
Free tierYesNo
CategoryTechnologyDeveloper Tools

Identical on both: platforms (Web), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Envoy

  • xDS dynamic configuration
  • Protocol breadth
  • Filter chain architecture
  • Observability by default
  • Outlier detection
  • Traffic shaping
  • mTLS termination and origination
  • Hot restart

Only in GNAT Pro

Nothing recorded that Envoy does not also cover.

What people use each for

The jobs each tool is most often brought in to do.

Envoy

  • Acting as the data plane under a service mesh or Gateway API implementation, which is how the overwhelming majority of deployments use itnot GNAT Pro
  • An edge or API gateway that needs per-route retry budgets, circuit breaking and outlier detection rather than round-robin proxyingnot GNAT Pro
  • Migrating traffic between service versions or between a monolith and its replacement, using weighted splits and shadow trafficnot GNAT Pro
  • Standardising observability across a polyglot estate, so that latency, error rates and tracing look the same regardless of the language a service is written innot GNAT Pro

GNAT Pro

  • Building certified avionics software meeting DO-178B/C standardsnot Envoy
  • Developing automotive embedded systems with ISO-26262 compliancenot Envoy
  • Integrating Ada, C/C++, and Rust components in single codebasenot Envoy
  • Managing software supply chain vulnerabilities and SBOMsnot Envoy
  • Supporting long-lived software systems spanning decadesnot Envoy

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Envoy

  • The configuration surface is very large and hand-written bootstrap YAML runs to hundreds of lines for routing that Nginx expresses in twenty, which is why nearly every production deployment sits under a control plane and inherits that control plane's constraints as well.
  • xDS is the real API and it is not stable in the comfortable sense; the v2 API set was removed outright, resource types continue to be deprecated, and your control plane and Envoy binaries have to be upgraded roughly in step or the proxies stop accepting configuration.
  • Extending it properly means writing a C++ filter and building and maintaining your own Envoy binary; the alternatives are Lua, which adds per-request overhead, and proxy-wasm, whose ABI has remained effectively experimental for years with a real performance cost.
  • At sidecar density the per-proxy memory and CPU footprint is a measurable share of cluster capacity, since thousands of workloads each carry a full proxy, and this is precisely the cost that has pushed mesh projects towards node-level or ambient architectures.
  • There is no single vendor selling support for Envoy itself; you get the community plus control-plane vendors such as Solo.io and Tetrate, so an Envoy-level production bug is your own engineers in a C++ codebase unless a support contract happens to cover it.
  • Diagnosing why a request got a particular response involves reading config dumps, the stats endpoint and the RESPONSE_FLAGS codes in access logs rather than a readable error, which is a specific skill you must hire or spend months growing.

GNAT Pro

  • No pricing published on website; requires contacting AdaCore directly for quotes
  • Vendor indicates per-user, per-year subscription model but does not disclose specific costs

Pricing, plan by plan

Envoy

Free

No published plan breakdown. See the Envoy review.

GNAT Pro

On request

No published plan breakdown. See the GNAT Pro review.

Which should you pick?

Choose Envoy if

  • You need xds dynamic configuration.
  • You want to start without paying.
  • You also want protocol breadth.
Envoy review

Choose GNAT Pro if

Nothing in the data separates GNAT Pro from Envoy on the points above - pick on price and on how each one feels to use.

GNAT Pro review

Questions people ask

Is Envoy or GNAT Pro better?
Neither clearly leads. Envoy starts at Free and GNAT Pro at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Envoy or GNAT Pro?
Envoy has a free tier; the other does not. Paid plans start at Free for Envoy and On request for GNAT Pro.
Does Envoy or GNAT Pro run on more platforms?
Both run on Web, so platform support will not decide this one for you.
Can I use Envoy for free?
Yes. Envoy has a free tier, so you can try it without paying. GNAT Pro starts at On request.
What is Envoy best used for?
Envoy is most often used for acting as the data plane under a service mesh or gateway api implementation, which is how the overwhelming majority of deployments use it, an edge or api gateway that needs per-route retry budgets, circuit breaking and outlier detection rather than round-robin proxying, migrating traffic between service versions or between a monolith and its replacement, using weighted splits and shadow traffic, standardising observability across a polyglot estate, so that latency, error rates and tracing look the same regardless of the language a service is written in. Of those, acting as the data plane under a service mesh or gateway api implementation, which is how the overwhelming majority of deployments use it and an edge or api gateway that needs per-route retry budgets, circuit breaking and outlier detection rather than round-robin proxying are not what GNAT Pro is typically brought in for.
What can Envoy do that GNAT Pro cannot?
Envoy covers xDS dynamic configuration, Protocol breadth, Filter chain architecture, Observability by default.

Answered from the vendors’ own pages

Envoy: Should I run Envoy on its own, or under a control plane?

Almost always under one. Directly authoring xDS or static bootstrap configuration is viable for a handful of routes and becomes unmanageable beyond that. Envoy Gateway, Istio, Contour, Gloo and Consul all exist to generate that configuration for you.

GNAT Pro: How much does GNAT Pro cost?

GNAT Pro pricing is not published on the website. Customers must request a pricing quote by contacting AdaCore directly or speaking with a GNAT Pro expert.

Source
Envoy: How does it compare with Nginx or HAProxy?

Envoy is dynamically configured over an API and instrumented far more heavily; Nginx and HAProxy are faster to configure and lighter for straightforward reverse proxying. If you never need to change routing without a reload, Envoy is more machinery than the problem requires.

GNAT Pro: What is GNAT Pro licensing model?

GNAT Pro is sold on a per-user, per-year basis with no license locks. Customers can request pricing for their specific needs.

Source
Envoy: What does it cost?

Nothing to licence; it is Apache 2.0 and there is no paid edition. The cost is engineering time and, for most organisations, a commercial control plane or cloud service that packages it.

Envoy: Can I write extensions without C++?

You can write Lua filters or proxy-wasm modules in Rust, Go, C++ or AssemblyScript. Both carry per-request overhead compared with a native filter, and the Wasm path has been slower to stabilise than the project originally projected.

Envoy: Is it a CNCF project?

Yes, it is a graduated CNCF project licensed under Apache 2.0, which means the trademark and governance sit with the foundation rather than with Lyft or any vendor.

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